Can ANYONE please help me..

[9646gt]

OK I am running out of money trying to fix my 96 GT...it is running fine during normal driving...when you accelerate quickly or go WOT it stumbles and sounds so horrible...I replaced the plugs with NGK t55's and they came gapped at 54 I also SEA Foamed the motor and it smoked like crazy of course...even changed fuel filter...The car ran EXCELLENT right off the bat..then after about a tank and a half of gas it is running HORRIBLE again..changed plugs with Auto Lite 764 coppers and it is STILL hesitating...I gapped them at 53 (between 52 and 54 like told) and it hasnt helped..if anything it is almost a tad worse! The plug wires look to be brand new (had the car only 2 weeks) ford racing wires and like i said they seem GREAT..ran a bottle of fuel injector cleaner with no luck...cleaned CAI and still no luck...what can I try that wont cost me the last few bucks I have? Check engine code says stopped up cats bc the cats are gone...someone PLEASE help me out at 2.41 a gallon 14 miles to the gallon is killing me!

 

[Kilgore Trout]

Clean MAF, IAC

Replace PCV

Reset PCM

 

[97gtblue]

what grade gas are you running

 

[9646gt]

Will clean and or replace all of the above ASAP...
as for gas I have ran 87 89 93 and 93 with ocatane booster ..right no I am running 93 with fuel inj cleaner with no luck...This is very aggrivating..I love mustangs and now I finally have a GT and have a problem I can't solve..kinds hard to drive like this heh

 

[PowerSplash93]

try the tps if that doesnt fix it. it may have a bad spot in it.
matt

 

[CanadaStang]

OK I am running out of money trying to fix my 96 GT...it is running fine during normal driving...when you accelerate quickly or go WOT it stumbles and sounds so horrible...I replaced the plugs with NGK t55's and they came gapped at 54 I also SEA Foamed the motor and it smoked like crazy of course...even changed fuel filter...The car ran EXCELLENT right off the bat..then after about a tank and a half of gas it is running HORRIBLE again..changed plugs with Auto Lite 764 coppers and it is STILL hesitating...I gapped them at 53 (between 52 and 54 like told) and it hasnt helped..if anything it is almost a tad worse! The plug wires look to be brand new (had the car only 2 weeks) ford racing wires and like i said they seem GREAT..ran a bottle of fuel injector cleaner with no luck...cleaned CAI and still no luck...what can I try that wont cost me the last few bucks I have? Check engine code says stopped up cats bc the cats are gone...someone PLEASE help me out at 2.41 a gallon 14 miles to the gallon is killing me!

What was the cel code #?

 

[9646gt]

What was the cel code #?

I dont remember exactly what the CEL code was but i think it was a 40 something and the guy at auto zone said it was pointing to the cats being plugged...

 

[Thundermouse]

as long as it won't ping, run the lowest octane gas

 

[CanadaStang]

I dont remember exactly what the CEL code was but i think it was a 40 something and the guy at auto zone said it was pointing to the cats being plugged...

Hmmm.... I wonder if there were any other codes that came up? There are 4 different codes pertaining to the catalyst, without knowing which one or if there was more than the one code it's pretty hard to pin point. If you could get the code or codes I'm sure we could help you out.
Would it be one of these: PO420
PO421
PO430
PO431

 

[9646gt]

i want to say it was 420 but i could be wrong ...seems like there was either a 0 or 2 at the end...should i buy coil packs? Maybe worth while to change the TPS or IAC? they are all three kinda pricey but I really want to pin point this and get it taken care of...I dont like to drive it with it acting up and risk damaging it ..

 

[9646gt]

I am going to try checking MAF, TPS,IAC and maybe even plug wires with a volt meter..where can I find the propper specs for these? I know I need to test the ohms but I need to know what a normal reading is...will my Haynes manual tell me? Thanx for all the help so far...

 

[bham_gt]

Have you checked to make sure your plug wires aren't rubbing against any metal that could be grounding them out? If they've been changed especially, one or more of them could be rubbing somewhere.

 

[gtstangrunner]

How is the car at idle? If its only hesitating at WOT it could be a fuel delivery problem. Did you check the pump, I saw you changed the filter. Your computer could be spazzing out on you. My car started hesitating real bad and about 3 days later the headgasket blew . I had looowwww compression in like every cylinder. I would try to get it on the dyno and that will most likely pin point the problem.

 

[Dan_Soprano]

OK I am running out of money trying to fix my 96 GT...it is running fine during normal driving...when you accelerate quickly or go WOT it stumbles and sounds so horrible...I replaced the plugs with NGK t55's and they came gapped at 54 I also SEA Foamed the motor and it smoked like crazy of course...even changed fuel filter...The car ran EXCELLENT right off the bat..then after about a tank and a half of gas it is running HORRIBLE again..changed plugs with Auto Lite 764 coppers and it is STILL hesitating...I gapped them at 53 (between 52 and 54 like told) and it hasnt helped..if anything it is almost a tad worse! The plug wires look to be brand new (had the car only 2 weeks) ford racing wires and like i said they seem GREAT..ran a bottle of fuel injector cleaner with no luck...cleaned CAI and still no luck...what can I try that wont cost me the last few bucks I have? Check engine code says stopped up cats bc the cats are gone...someone PLEASE help me out at 2.41 a gallon 14 miles to the gallon is killing me!

so the car does or does not have cats?

 

[Mike97gt]

The car ran EXCELLENT right off the bat..then after about a tank and a half of gas it is running HORRIBLE again..

by this do you mean it ran great right after the fuel filter change?? then ran horrible after a tank or so of fuel.. if this is the case you may have something contaminating the fuel supply.. and clogging the fuel filter...

please provide more info..

 

[9646gt]

The car doesn't have cats its straight pipe from headers to mufflers...It seems to idle jsut fine..I think it has a bad heater core but that doesn't explain the hesitation...i am leaning towards the TPS not reporting WOT to the ECU...if someone can tell me how to test the ohms of the tps with a volt meter it may tell me right away..I am going to have the codes ran again today if it doesnt rain and have them run with engine running this time also...

As far as fuel delivery the fuel pressure gauge under the hood shows at or above 40 even when reving the motor while idleing..it goes up but never really seems to drop any... could the seamfoam I ran into the intake manifold have been what made it run so well the first time? meybe something is building up very quickly and this removed it? i sucked it straight into a vacume and the engine NEVER killed itself out like i figured it would...

thanks so much for your guys help and PLEASE keep any suggestions comming...

also is it bad if the plug wires cross over each other quite a bit? I always heard it was.... this sputter has to be fixed

 

[Mike97gt]

I dont remember exactly what the CEL code was but i think it was a 40 something and the guy at auto zone said it was pointing to the cats being plugged...

there is no code for the cats being plugged... this is why you dont listen too the auto zone guy... look at the scan tool yourself and write the code down..

there is no code 40 and no code for cats being "stopped" up

since your car has no cats i would ignore the cat codes... probally a cat ineffecincy code..

but keep in mind the computers may have built in logic too create driveability problems when cat codes have been running for awile... ( this is done so you bring the car in too have the emmisions work done) i know GM has done this.. and i would not be surprised if ford has done this on early obd2 cars...

to fix the cat codes all you need is mil eliminators...

i stoped into a auto zone once with a friend of mine in his truck too get a code read.. i already knew what was wrong with it i just wanted too be a dick and **** with the autozone guy..

the truck was a 2001 explorer with a po401 innsuficent egr flow... and this guy reads the code and then trys too sell me a egr valve

i told him why he was wrong and explaned too him that the DPFE sensors on just about all fords built around that time goes.. ( these are the small black sensors.. not the big old metal ones.. you can tell if your car has one because it's a standalone unit with no bracket) and then i told him he should not try and diag cars.. just give the code and let them take it from there..

 

[9646gt]

by this do you mean it ran great right after the fuel filter change?? then ran horrible after a tank or so of fuel.. if this is the case you may have something contaminating the fuel supply.. and clogging the fuel filter...

please provide more info..

Sorry i was so aggrivated that I messed up there..I changed the fuel filter last ..it ran GREAT after only seafoam and plugs ..i changed filter as a last resort after the tank and a half where it started running crappy again...it doesnt even sound right when you rev the motor at idle....sounds nothing like it did when it was running so well....

 

[9646gt]

there is no code for the cats being plugged... this is why you dont listen too the auto zone guy... look at the scan tool yourself and write the code down..

there is no code 40 and no code for cats being "stopped" up

since your car has no cats i would ignore the cat codes... probally a cat ineffecincy code..

but keep in mind the computers may have built in logic too create driveability problems when cat codes have been running for awile... ( this is done so you bring the car in too have the emmisions work done) i know GM has done this.. and i would not be surprised if ford has done this on early obd2 cars...

to fix the cat codes all you need is mil eliminators...

Ill do everything in my power to get those codes ASAP ...i am just having a hard time understanding why after that tank and a half of gas the whole car turned around again...all i did was plugs and the seafoam...Look like I will learn alot from this experience heh

 

[Mike97gt]

Ill do everything in my power to get those codes ASAP ...i am just having a hard time understanding why after that tank and a half of gas the whole car turned around again...all i did was plugs and the seafoam...Look like I will learn alot from this experience heh

yeah that is kind of weird how it ran well at first...

i dont like the use of aftermarket plugs in ford motors.. use the motorcrafts.. I have had so many problems related too non-motorcraft plugs in the past... now it's the first thing i look for..

when did it first start running like crap.. after or before the first plug change...

plus does it idle ok.. i need too know this too help..